Breech-loading mechanism for ordnance



Dec. 2,1947. .w. MOLINSI 2,431,954

BREECH LOADING MECHANISM FOR ORDNANCE Filed Nov. 23, 1943 I Aid/ Patented Dec. 2, 1947 BREECH-LOADING MECHANISM FOR ORDNANCE Desmond Walter Molins, London, England, as-

signor to Molins Machine Company'Limited,

London, England Application November 23, 1943, Serial No. 511,454

a In Great Britain September 29, 1942 1' Claim. (0113943) Thisinvention concerns improvements in or relating to ordnance.

It is found that in loading ordnance automatically, where the round is not being pushed right up to the time when it has substantially wholly entered the breech, thereisa tendency for the round to be held up before it can get home. This fact reduces the rate of fire, and is particularly objectionable in the case of an automatic gun as it requires manual manipulation to rectify the stoppage.

The present invention is limited to ordnance which is automatically loaded and in which the round is pushed part of the Way into the breech after which the round is left to continue its forward travel into the breech on its own momentum.

Such ordnance is referred to hereinafter as ordnance as specified.

This holding up of the rounds in the circumstances described above has been found to be due to a tendency for the rear end of the round, as the latter travels rapidly forward after it has left the rammer, to vibrate slightly on entering the breech.

According to the present invention there is provided in breech loading mechanism for ordnance as specified, separate guide-elements extending rearwardly from each side of the breech and arranged on opposite sides of a round being fed into the breech and adjusted so as to provide a chamber-wall clearance for the base of a round just sufficient to allow the base to pass there-between whilst steadying the base, so as to facilitate full entry of the round into the breech, the guides being flared to enable the round to pass between them.

It is necessary to ensure the minimum clearance between the guides and the flange of theround to prevent a vibration and accordingly in the present invention the guides are provided as separate guide elements located on opposite sides so that they can be accurately positioned to provide a fine tolerance and, in order to enable the round to pass between them, the guides must be flared at their entry.

The invention will be more fully described with reference to the accompanying drawings in Which- Figure 1 is a front elevation of the breech of a six-pounder gun showing the application of the invention thereto.

Figure 2 is a plan of Figure 1.

Referring to the drawings the breech mechanism shown is for a six-pounder gun embodying automatic loading and firing devices. These devices form no part of the present inventionbut may be studied by reference to United Statespatent applications, Serial No. 488,454, filed May .25,

1943, now Patent No. 2,418,656, issued April 8,.

1947, and Serial No. 495,522, filed Jul 20', 1943. The parts of the loading and firing mechanism shown in the present drawings are similar in all material respects to those illustrated and de' scribed in the applications referred to.

Referring to Figure 1, the breech is shown closed and it will'be seen that vertical plates I and 2 are fixed to the breech, and as seen in Figure 2 located behind the sliding breech block II), the plates being arranged to lie on opposite sides of an oncoming round. The left hand plate I is attached to the breech by means of four studs 3 which are shouldered as indicated at 4, Figure 2, so that the plate is a close fit on the shoulders of the studs. When the plate is finally adjusted in position it is permanently located by a pair of dowels 5. The reason for this method of fixing is that it isoccasionally necessary to remove the plate and its accurate location on the breech is a matter of importance. The right hand plate 2 is fixed by bolts 6 to a structure I, Figure 2, forming part of a cam plate 8 which is in turn fixed to the breech of the gun.

Guides II and I2 provided with suitably outwardly curved or flared operative faces as shown in Figure 2 are fixed to, or integral with, the plates I and 2 respectively. The outward curves or flare of the guides I I and I2 serve to facilitate the entry of the rounds between the parallel guiding faces of the guides II and I2. As shown in Figure 1, the centres of these guides are positioned in a horizontal plane passing through the axis of the gun bore.

The parallel guiding faces of the guides II and I2 are spaced to give a chamber wall clearance of 0.01" at each side of the largest diameter of the round, in the example being described. This spacing is found to be effective in reducing the vibration and tendency for hold-ups of the round, since steadying the rear end during ramming is important. An extension or lug 9 on the plate 2 projects inwardly towards the centre of the breech. The breech-block in the gun described is of the semi-automatic type and is 'caused to open automatically and eject the spent cartridge-case near the end of the run-out. The rounds are normally held clear of the breech and after the spent case has been ejected, the nose is allowed to drop downwardly and will fall on top of the open breech-block whilst the base will be engaged by a rammer so as to carry the round forwardly.

thereon. Thus the extension or lug 9 reduces the shock on the falling nose to some extent.

The vertical sides Ill and H2 of the breech block are in line with the guides II and 12, re

spectively, when the breech is open. so that the base of the round is guided substantially up to. V

the entry of the breech.

What I claim as my invention and desire to secure by Letters Patent is:

In breech loading mechanism for ordnance of the type embodying a vertically sliding breech block having a concave upper surface onto which the nose of a round is arranged to be dropped from above during loading for presentation to the breech, guide means in the path of the falling round so constructed and arranged as to deflect the round when dropped and cause the nose thereof to slide down one side of said concave surface and tend to be centralized thereon, and separate guide-elements extending rearwardly from opposite sides of the breech and arranged on opposite sides of the path of a round being fed into the breech and adjusted so as to provide a chamber-wall clearance for the base of a round just sufficient to allow the base to pass therebetween whilst steadying the base, so as to facilitate full entry of the round into the breech, the

rear portions of the operative guiding surfaces of said guide-elements being outwardly flared to enable the-round to pass between them.

DESMOND WALTER MOLINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 895,481 Meigs et a1 Aug. 11, 1908 1,128,555 Vickers Feb. 16, 1915 2,151,288 Waninger Mar. 21, 1939 1,705,659 Colo-n Mar. 19, 1929 2,112,853 Lucht et al Apr. 5, 1938 69,519 Weeks Oct. 1, 1867 512,743 Parkhurst Jan. 16, 1894 2,365,459 Dobremysl Dec. 19, 1944 

